1、建立触发器,订单表中增加订单数量后,商品表商品数量同步减少对应的商品订单出数量,并测试
sql
mysql> create trigger orders_after_insert_trigger after insert on orders for each row
-> update goods set num=num-new.onum
-> where gid=new.gid;
Query OK, 0 rows affected (0.01 sec)
2、建立触发器,实现功能:客户取消订单,恢复商品表对应商品的数量
sql
mysql> create trigger orders_after_delete_trigger
-> after delete on orders for each row
-> update goods set num=num+old.onum
-> where gid=old.gid;
3、建立触发器,实现功能:客户修改订单,商品表对应商品数量同步更新
sql
mysql> create trigger orders_after_update_trigger
-> after update on orders for each row
-> update goods set num=num+(old.onum-new.onum)
-> where gid=new.gid;
使用mydb7 openlab库
4、创建提取emp_new表所有员工姓名和工资的存储过程s1
sql
mysql> delimiter //
mysql> create procedure s1()
-> begin
-> select name,incoming from emp_new;
-> end //
Query OK, 0 rows affected (0.01 sec)
mysql> delimiter ;
mysql> call s1();
+------+----------+
| name | incoming |
+------+----------+
| 张三 | 4000 |
| 李四 | 3500 |
| 王五 | 2000 |
| 赵六 | 7500 |
| 荣七 | 8500 |
| 牛八 | 7300 |
+------+----------+
5、创建存储过程s2,实现输入员工姓名后返回员工的年龄
sql
mysql> create procedure s2(in in_name varchar(11),out out_age int)
-> begin
-> select age into out_age from emp_new where name=in_name;
-> end //
Query OK, 0 rows affected (0.01 sec)
mysql> delimiter ;
mysql> call s2('张三',@age);
Query OK, 1 row affected (0.00 sec)
mysql> select @age;
+------+
| @age |
+------+
| 35 |
+------+
6、创建一个存储过程s3,有2个参数,传入部门号,返回该部门的平均工资
sql
mysql> create procedure s3(in in_dept int,out avg_sal float)
-> begin
-> select avg(incoming) into avg_sal from emp_new where dept2=in_dept;
-> end //
Query OK, 0 rows affected (0.01 sec)
mysql> delimiter ;
mysql> call s3(101,@avg_sal);
Query OK, 1 row affected (0.00 sec)
mysql> select @avg_sal;
+----------------+
| @avg_sal |
+----------------+
| 3166.669921875 |
+----------------+
1 row in set (0.00 sec)